Breach of Earth's Magnetosphere
Summary
NASA’s THEMIS mission has overturned a long-standing belief about the interaction between solar particles and the earth’s magnetic field. The earth’s magnetic field forms a protective field around the earth, shielding us from the solar wind that is constantly streaming towards the planet. This shield is called the magnetosphere.
But the sun has a magnetic field of its own, as well, which the solar wind carries toward earth. The THEMIS spacecraft fleet recently observed that 20 times more solar particles get into the earth’s magnetosphere when the sun’s magnet field aligns with that of the earth, than when it is pointed in opposite direction.
In the past, researchers found that the energy from the sun gets into the earth’s magnetic field during periods when the sun’s magnetic field points southward. Now it has been found that the particles get into the earth’s magnetic field when it points northward. These solar wind particles that get into the earth’s magnetic field, are energized, and become the earth radiation belts, which can damage spacecraft and harm astronauts.
Keywords: THEMIS project, solar wind, magnetosphere, radiation, solar storm
